fetching private repositories from GitHub app

Question

I'm building a web app that integrates with GitHub API (authentication). I'm trying to fetch the user's repositories both public and private. But both without accessToken and with accessToken return public repos only.

1. authentication

  const provider = new GithubAuthProvider();
  provider.addScope('repo');

  const PopupSignIn = async () => {
     const result = await signInWithPopup(auth, provider);
     const credential = GithubAuthProvider.credentialFromResult(result);
     setToken(credential.accessToken)
     return credential;
  };

2. fetching repositories
   user here is the auth credential got from getAuth()

PopupSignIn().then(() => {
   fetch(
      `https://api.github.com/users/${user.reloadUserInfo.screenName}/repos`,
      { headers: { authorization: token } }
   )
});